Work chuck



United States Patent '10 WORK CHUCK Application September 11, 1957,Serial No. 683,256

6 Claims. (Cl. 279-6) This invention relates to a work holding chuckdevice generally and more particularly to means providing for radial andangular adjustment of a work holding jaw member relative to a rotatablespindle.

In machining operations where close tolerances-are necessaryconsiderable time is lost and great f expense incurred in the timenecessary to set up the equipment to insure such limits.

It is here proposed to provide a work holding chuck device for use in alathe or other machine tool whereby a work holding jaw member may beradially and angularly adjusted relative to the driving spindle of thework tool without undue effort and loss of time and with micrometeraccuracy.

It is proposed to make use of screw `or other positive deflection meansbetween two members of different stillness, one of said membersconnecting the work holding jaw member to the rotatable spindle, forseparating such members and whereby the relative deilection of saidmembers is inversely proportional to'their stillness. With such membersdisposed in parallel relation7 `and concentric with the axis of rotationof the spindle, a radial adjustment of the work holding jaw member maybe effected. By having the members disposed in unparallel relation anangular adjustment of the work holding member relative to the spindlemay be obtained.

The proposed work holding chuck device is relatively inexpensive tomanufacture and assemble and may make use of coarse screw adjustments toobtain small relative movement with micrometer accuracy.

In the drawing:

Figure 1 is a sketch of parts arranged to show the principle employed inthe proposed work holding chuck device.

Figure 2 is a cross-sectional view of a work holding chuck deviceincluding the principles of this invention.

Referring to the sketch, two beams of different stillness A and B areshown secured to a base member C. A turn screw D is threaded throughbeam B and is engaged with beam A. As the screw D is turned to move thet'wo beams apart the deilection of the beams is inversely proportionalto their stiffness. Assuming that beam A is one thousand times (1000) asstill as beam B, the adjustment of the screw D to increase the distancebetween the beams by one thousandth of an inch (.001) will move beam A 1micro-inch (.00000l) and beam B will move 999 micro-inches (.000999).

The accuracy of the l micro-inch motion of beam A will be determined bythe ability to increase the distance between the beams by the specifiedone thousandth of an inch and the accuracy of the determination of thestiffness ratio between the beams. Such factors, once determined, may beincorporated with a work holding chuck device to provide extremelyaccurate radial and angular alignment of a work member as is hereafterdescribed.

Referring to Figure 2, a rotatable spindle member 10 adapted to bedriven by suitable means is shown to include a base member 12 having anannular ring 14 secured ice thereto as by threaded fasteners 16. Postsor beams 18 are secured to the annular ring 14 and support anintermediate llange member 20 in parallel spaced and concentric relationto the spindle member 10. l'I'he ends of the posts or beams 18 areundercut as at 22 and received in guide holes 24 and 26 formed in theannular ring and llange member respectively, and are welded theretoas at28 and 3o. l The Work holding jaw member 32 is disposed in spacedrelation to the flange member 20 and concentric with the flange andspindle members. .The jaw member includes jaw parts 34 and 36 engagingand holding'centering jaw members 37 and 38 which in turn receive andhold the workpiece 40. Any suitable work holding jaw member may be usedother than the one'which has been illustrated. vThe work holding jawmember 32 includes conically disposed beam members 42 extended outwardlyas spider arms or spokes and secured to an annular ring 44 which is inturn secured to the llange 20 as by fasteners 46.

, The llange 20 has a rod 48 secured centrally thereto as by theconnecting collar 50 and'fasteners 52. The rod is concentricallydisposed relative to the spindle `10 and depends from the flange towithin a recess 54 formed in the base member 12. A collar 56 provided onthe end of the rod 48 is engaged `by a turn screw 58 threaded throughthe side wall of the base member 12.

Adjustment of the turn screw 58 will deflect rod 48 relative to thebeams 18 an amount inversely proportional to the respective stillness ofthe rod and beams and will in turn cause a radial adjustment of thellange 20, and the work holding jaw member 32 secured thereto, relativeto the spindle 10.

The Work holding jaw member 32 also includes depending rod members 60received through suitable openings 62 provided in the flange member andhaving the ends thereof including Collars 64 disposed adjacent the end66 of a sleeve portion 68 formed from the flange member 20. Turn screwmeans 70 threaded through the depending ends 66 of the sleeve portion ofllange 20 are engaged with the collar 64 of the rod 60 and will dellectthe rod relative to the spokes or beams 42 an amount inverselyproportional to their respective stillness. Since the beams are notdisposed in parallel relation to the rods 60 an angular adjustment ofthe work holding jaw member 32 is effected relative to the llange 20 andconsequently to the spindle 10.

With the proposed work holding chuck device it should be apparent thatthe adjustment of the turn screws 58 and 70 will elect a radial orangular adjustment of the work holding jaw member 32 for centering theworkpiece 40 relative to the rotatable spindle 10.

What is claimed is:

l. A Work holding chuck device comprising a rotatable spindle memberreceivable within a driving member and including means for holding awork member substantially centered relative to the axis of rotation ofsaid spindle, said chuck device including a work holding jaw memberspaced apart from said spindle and having separate connecting members ofdierent stillness secured therebetween, and turn screw means threadedthrough one of said connecting members and engaged with another thereofof dierent stillness for dellecting said connecting members from theirnormal position an amount inversely proportional to the ratio ofstillness therebetween and for simultaneously effecting an adjustment ofsaid work jaw member relative to the axis of rotation of said spindle.

2'. A work holding chuck device comprising a rotatable spindlel memberhaving a work holding jaw member spaced apart therefrom and connectingbeam members secured therebetween, a rod member connected to said workholding jaw member and disposed in spaced relation to said beammembers,'said rod and beam members being of different relativestiffness, and turn screw means engaged `between said rod and beammembers for deflecting each of said rod and beam members from theirnormal position an amount inverselyproportional to thevratio ofstiffness therebetween andfor effecting an-adjustment of said work jawmember connected thereto.

3. The Work holding chuck device `of claim 2 wherein said rod and beammembers are,l initially in substantially parallel spaced relation foreffecting radial adjustmentof said work jaw member connected thereto.

4. The work holding chuck "device of claim 2 wherein said rodand beammembers are disposed in non-parallel spaced relation for effectingangular adjustment of said work jaw member connected thereto.

5. The work holding chuck deviceof 'claim y2 having some of said rod andbeam'members disposed initially in substantially parallel spacedrelation and other of lsaid rod and beam members disposedin'non-parallel spaced relation, and separate turn screw means betweenthe rst and last-mentioned group .of rod and beam members for separatelyadjusting the radial and angular disposition, respectively, of said workjaw member connected thereto.

6. A work holding chuck device including a rotatable spindle having aWork holding jaw memberdisposed in concentric spaced relation thereto,an intermediatel ange Cil member disposed between said spindle and saidwork holding `jaw member, peripherally disposed beam members connectedbetween said spindle and said ange and a rod member secured to anddepending from said flange member to a position next adjacent saidspindle, conically disposed spoke members connected between said angeand said work holding rjaw member and rod members secured to anddepending from said jaw member to a position next adjacent said'angemember, turn screw means engaged between said spindle and said rod andoperativefor radiallyzadjusting said flange relative to said spindle,and other turn screw means engaged between saidange and said rod membersand operative for angularly adjusting said work holding member relativeto said ange, said rst and second-mentioned turn screw means incombination providing means for the radial and angular adjustment ofsaid work jaw member relative to said spindle.

Y -References'Cited inthe le of this patent UNITED STATES PATENTS1,812,455 Stowell June 30, 1931 2,538,289' IArms Ian. 16, 1951 2,719,721Grobey Oct. 4, 1955

